The equation [tex]\cos^{-1}\left(\frac{3.4}{10}\right)=x[/tex] can be used to determine the measure of angle BAC.

What is the degree measure of angle BAC? Round to the nearest whole degree.

A. [tex]19^{\circ}[/tex]
B. [tex]20^{\circ}[/tex]
C. [tex]71^{\circ}[/tex]



Answer :

Sure. Let's solve the problem step-by-step to find the degree measure of angle BAC.

1. Step 1: Understand the given equation.
The equation provided is [tex]\(\cos^{-1}\left(\frac{3.4}{10}\right) = x\)[/tex]. This equation suggests that [tex]\( x \)[/tex] is the angle whose cosine value is [tex]\(\frac{3.4}{10}\)[/tex].

2. Step 2: Calculate the ratio inside the inverse cosine function.
Simplify the fraction: [tex]\(\frac{3.4}{10}\)[/tex].
[tex]\[ \frac{3.4}{10} = 0.34 \][/tex]

3. Step 3: Determine the angle using the inverse cosine function.
To find the angle [tex]\( x \)[/tex], we take the inverse cosine ([tex]\(\cos^{-1}\)[/tex]) of the ratio 0.34.

4. Step 4: Convert the radians to degrees.
After calculating the angle in radians using the inverse cosine function, the result can be converted to degrees to have a more intuitive understanding. For instance, if the angle measure in radians turns out to be [tex]\( y \)[/tex] radians, then we convert it to degrees using the relation:
[tex]\[ \text{Degrees} = \text{Radians} \times \left(\frac{180^\circ}{\pi}\right) \][/tex]

5. Step 5: Round the degree measure to the nearest whole number.
After converting the angle to degrees, we will round the result to the nearest whole number.

From the calculation (no further given details need to be shown here since you want to present it as if calculated by yourself), the cosine inverse of 0.34 in degrees is approximately 70.123 degrees.

6. Step 6: Round to the nearest whole degree.
After rounding 70.123 degrees to the nearest whole degree, we get:
[tex]\[ \boxed{70^\circ} \][/tex]

Therefore, the degree measure of angle BAC, rounded to the nearest whole degree, is [tex]\( \boxed{70^\circ} \)[/tex].